2nd generation Prius skid plate from Prius Offroad

A thief can steal a Gen 2 cat in less than 60 seconds... With a cat shield they can still make the cuts at the front and back of the shield, but they can't get the cat out afterwards without popping out the shield, so they're likely to look for an easier theft and pass your car by. And I just went and looked at Skid Plate: 2004-2009 Prius and this would prevent the front cut with the sawz-all. As in if thieves are looking for a fast quick grab and they're more willing to pass on ones that take longer.

That being said there's some problems with doing oil and filter changes with Offroad Prius' design and I'm not impressed with lack of mounting bolts. Also because it's metal it's gonna bend when you hit something and that can make the mounts come loose.

You could save alot of money and alot of weight buy using black corrogated plastic (Coroplast) which is like thick cardboard but made of plastic and it's more than strong enough to protect the underside of your car from most everything you'd run into and if you hit something really bad it's gonna fail more like a crumple zone absorbing the force of the impact rather than a plate of steel or aluminum that's going to send the impact into the frame rails causing failure where the metal is bolted in place. And repair work will be way easier with corrugated plastic compared to trying to make sheet steel flat again.

And if you want to make it really nice and cover the whole car in a solid belly pan of that type of plastic you could spray some undercoat paint on top, which will make for great soundproofing and way more of a deterrent to potential thieves and a tiny bit better gas mileage too.

 

Somehow applying a wall of plastic beneath the catalytic converter does not seem like a great idea to me. Either the plastic melts (or worse, ignites) from the cat's heat, or all the trapped heat is forced up into the car. It could melt the insulation on the oxygen sensor wires in that region. Possibly punching a bunch of ventilation holes in the plastic would let most of the hot air escape and cool things off some, but it might not be enough to prevent melting from the radiant heat. Coroplast melts at 324F.

The surface of a cat is definitely hot enough to melt plastic. A plastic shopping bag blew under one of our cars years ago and it instantly melted onto the cat. Don't know if it caught fire or not, but there was a nasty black goo on the cat for a long time, and the car smelled like a lit candle for a month.

 

yea... obviously you use different material along the exhaust line, that just goes without saying...

 

Yeah, I here ya... If I hadn't had a boss in the early 90's in a campervan shop expecting me to get three days of work done in 3 hours I'd of burned out too. But it's amazing how quickly you get work done when you've dealt with that kind of pressure from inept idiots for years. So often I don't know how I'm going to get something done and keep working on it on as if I am and get pleasantly surprised because of that guy who was surrounded by maids and servants all his life.

But back to the project, there's plenty of people on youtube who've built all kinds of interesting things with this material... For your needs since we just had and election, just start gathering up old signs and get under there with some short screws and a screwdriver gun and screw them into the other plastic parts while making sure there's nothing behind it that will get damaged. It's super easy and free and you'll be done faster than you think if you don't overthink it.

As for the oil changes, the openings they made for that on first glance seem way too small... I'd not want to have to get an oil filter out from under that.